Heretofore, such as shown in prior U.S. Pat. No. 3,943,974 dated Mar. 16, 1976, control valves for fluid actuators have been provided in which fluid is quickly exhausted from a fluid valve actuator when the main flowline pressure reaches a high or low pressure outside the desired fluid pressure operating range. However, such prior control valves have utilized a slide valve and piston which have been urged continuously to an inner seated position. The prior control valves have been reset by pulling outwardly on the manual knob and a detent is then pushed inwardly to hold the slide valve in an outer position until the operating fluid pressure has built up a predetermined amount for release of the detent. During normal operation the slide valve is in an outer position with the upper portion of the slide valve outward of the housing exposed to the atmosphere. Many of these control valves are utilized in offshore facilities exposed to sea water and other conditions which offer prolonged use and time might permit the upper portion of the slide valve outside the housing and adjacent the knob to be coated with scales, crusts, or other types of foreign matter. This could impede or restrict the inward movement of the slide valve within the housing under certain conditions.